@mixin font-stack($ff, $weight: normal) {
  font-family: #{$ff}, Helvetica, Arial, sans-serif;
  font-weight: $weight;
}

%font-200 { @include font-stack('Ubuntu', 200) }
%font-300 { @include font-stack('Ubuntu', 300) }
%font-500 { @include font-stack('Ubuntu', 500) }
%font-700 { @include font-stack('Ubuntu', 700) }
